LG K51 Pros and Cons / Is LG K51 a good phone?

LG K51 falls in the mid-range. It offers most of the useful smartphone features at a budget price. K51 is the successor to LG K40 which itself is a decent mid-ranger.

If the MetroPCS/T-Mobile smartphone lineup is considered, the LG K51 falls between Aristo 5 & Stylo 6. In this post, we are going to find out the pros and cons of LG K51. Let’s also check out, how does it compare to K40, Aristo 5 & Stylo 6 –


LG K51 Pros & Cons

Let’s begin with the Pros –


1. Big Screen with 19.5:9 Aspect Ratio

LG K51 pros and cons - display
LG K40 (Left) & LG K51 (Right)


The highlight of K51 is its big 6.53 screen with a notch. The notch design offers more screen estate in less space. K51’s screen is bigger than Stylo 5 but smaller when compared to Stylo 6.

K51 looks like a phone from the higher segment when kept beside K40. K40 comes with a 5.7 inches screen. It is smaller in size but fits nicely in hand.


2. Android 10 out of the box

lg k51 android 10

Except for Boost Mobile K51, the rest of the variants come with Android 10 out of the box. The K51 Boost Mobile comes with an Android 9 operating system.

LG Aristo 5 & Stylo 6 are also running on Android 10.

3. Triple Rear Camera Setup

lg k51 vs k40 camera
LG K40 (Left) & LG K51 (Right)

LG K40 comes with a single 13MP camera on the rear.

On the other hand, K51 offers triple cameras on the back. Apart from the main 13MP camera, there is a 5MP wide-angle  (115°) camera & a 2MP depth sensor for the bokeh effect.


4. Wifi Calling Support

lg k51 wifi calling

LG K51 also offers Wi-Calling. However, it’s is a carrier dependant feature.

Boost Mobile, MetroPCS, T-Mobile K51 support Wi-Fi calling. I’m not so sure about the Verizon K51.

5. Expandable Memory

lg k51 expandable memory

The internal storage space on K51 is 32GB. Almost half of this space is used by the system memory. The usable storage space is hardly 16 GB.

The good thing is we can expand the storage space using a memory card. It supports micro SD card up to 256GB.



6. Headphone Jack 3.5 mm

lg k51 headphone jack 3.5mm

Nowadays many of the flagship devices are done away with the 3.5 mm headphone jack.

Luckily, K51 comes with a headphone jack located at the bottom as shown in the above picture.


8. Adoptable Storage Support

lg k51 move apps to sd card

The K51’s low internal memory can be expanded with an SD card. However, the apps and games still occupy the internal storage space.

The solution to this problem is the adoptable storage feature. We can move the apps to SD card on K51 and make it the default storage space for apps and games.

Please refer to the above screenshot.  The SD card is partitioned into 2 parts. One part is being used as internal storage.

LG K51 Move Apps to SD Card

7. Multitasking with Dual Screen & Pop-up window

lg k51 dual screen

LG K51 offers multitasking just like a computer.

There are 2 modes of multitasking. Using the multi-window feature we can split the screen into 2 and use 2 apps at once.

lg k51 pop up window

Using the pop-up window feature, we can run an app in the mini-window format as shown above. We can minimize this app and launch a new pop-up window. This way we can work on many apps at once.

LG K51 Dual Screen & Pop-up Window 

8. LED Notification Light

lg k51 notification light

The notification light was also offered on LG K40. K51 also offers Blink LED to notify missed calls, messages, and app notifications.

9. USB Type-C Charging Port

lg k51 usb type c

The Type-C USB Port is offered for the first time in LG KSeries. LG K40 comes with a Micro USB Port.

10. Sensors

lg k51 sensors

All the useful sensors are offered by LG K51.

lg k51 gyroscope vr
LG K51 Google Cardboard App

It comes equipped with Accelerometer, Ambient Light Sensor, Digital Compass (Magnetometer) & Gyroscope (VR Headset Compatible).

11. USB OTG Compatible


I connected a Pen Drive & Mouse to my K51 using an OTG adapter. Both worked fine.

LG K51 OTG support

We can increase the mouse pointer size in the accessibility settings.


12. Fingerprint Scanner

lg k51 fingerprint sensor

The fingerprint scanner in K51 is located at the back of the phone as shown above.


lg k51 fingerprint setup

We can add multiple fingerprints for screen unlocking.





1. Poor Hardware

lg k51 processor
LG K40 (Snapdragon) vs LG K51 (Mediatek) Processor

If you’ll observe closely, you’ll see a lot of cost-cutting on LG K51 as compared to its predecessor K40.

First of all, LG has opted for the cheaper entry-level Mediatek Processor for K51. Until now, every K series phone came with a Snapdragon Processor. Mediatek CPU’s are comparatively cheaper.

2. No Fast Charging Support

LG K51 Fast Charging

Quick Charge support is getting quite common nowadays. It’s a must-have feature. The Fast Charging support is still not offered on LG K series smartphones.

does lg k51 support fast charging
LG Stylo 6 fast charging

The fast-charging icon on LG Stylo 6 can be seen in the above screenshot. A battery with a lightning symbol.

3. Low Screen Resolution

lg k51 screen resolution

The Full HD screen resolution is offered on LG Stylo series smartphones which fall in a segment higher than the K Series.

The HD resolution on K40 looked fine because of the small screen size. However, for a big 6.5 inches screen, the HD resolution looks quite pixelated.  K51 offers a screen resolution of 1560 x 720 pixels with a pixel density of around 264 PPI.

4. Root – TWRP – Bootloader Unlocking – Custom ROM status

lg k51 lmk500 root

LG K51 comes with a locked bootloader that cannot be unlocked. The “bootloader unlock command” simply reboots the phone.

With a locked bootloader, we cannot flash a custom recovery such as TWRP. Without TWRP, we cannot flash Magisk or SuperSU root file.

LG K51 cannot be rooted as of now.

LG K51 Root, Bootloader Unlock, TWRP

5. Not compatible with MHL / HDMI Alt Mode

lg k51 hdmi alt mode

You may be hoping to mirror your K51 screen on the TV using an HDMI / MHL adapter. Don’t keep your hopes high. The HDMI alt mode support is only offered on the flagship LG devices belonging to V & G Series.

LG K51 is not compatible with HDMI Alt Mode/MHL/Slimport.

6. Face Recognition/Unlock not supported

lg k51 face recognition unlock
LG K51 (Left) vs LG K40 (Right) Face Recognition


It quite surprising that the face unlock feature is removed on LG K51. Face recognition was offered on K40. You can refer to the above screenshots.

Face unlock is more convenient than Fingerprint in my opinion.

7. Not compatible with Fortnite

lg k51 fortnite compatible

The limited 3 GB RAM on LG K51 makes it incompatible with Fortnite. K51 could have been a good gaming phone if offered with at least 4GB RAM.


8. Does not support 5G

lg k51 5g compatible

The 4G technology has grown old by now. It will be obsolete in the coming years.

To remain future proof we need to opt for 5G phones. Unfortunately, as of now, only the LG flagship devices offer 5G technology.  K51 being a mid-range phone lacks 5G support.

9. Low internal storage & RAM

lg k51 ram & rom

Being a mid-range phone I expected at least 4GB RAM & 64GB storage from K51. The 3GB – 32GB combination seems quite insufficient as per today’s standards.

10. Does not support Wireless Charging out of the box

lg k51 qi charging

Wireless charging is an addiction once you get used to it. Being a mid-range phone, K51 lacks Qi charging.

However, we can make it Qi-enabled. Learn how to make it wireless charging capable –

lg k51 wireless charging

LG K51 Wireless Charging – How to Enable 

11. No “Cast” option for Screen Mirroring

lg k51 miracast

For wireless screen mirroring the phone should be Miracast enabled.

I searched for the “Cast” option on K51, but couldn’t find it anywhere.

We can still mirror our K51 screen to the TV using alternate options. Learn how to mirror LG K51 to Chromecast, Roku, Fire Stick, Samsung Smart TV, etc. –


lg k51 screen mirroring

LG K51 Screen Mirroring

12. Non-Removable Battery

lg k51 non removable battery

The removable battery was last offered on LG K20, as far as LG K Series is concerned. This way we can have a spare battery for emergency situations.

Unfortunately, K51 comes with a non-removable battery.

13. Lacks IR Blaster

lg k51 ir blaster

With the IR blaster support, the phone can be used as an all-in-one remote for all home appliances.

LG K51 lacks an IR blaster.

14. Durability

is lg K51 waterproof?

The front and back of the LG K51 is all glass. Once fall and the glass may shatter. K51 doesn’t use a Gorilla Glass. You should always use it with a cover and screen guard.

You should also keep it away from the water as it’s not waterproof.

15. No Selfie Flash

lg k51 front camera flash

One more useful feature omitted from K51 is the Selfie Flash. The Front camera flash was offered on LG K40 as evident in the above picture.


16. The default mode of navigation (Gestures) is annoying

lg k51 home and back button

On LG Android 10, the default mode of navigation is using Gestures. We don’t get the usual navigation bar with the Home, Back & Recent Apps buttons. This is quite annoying.

To good thing is, we can change these settings can get back the navigation bar with the home touch buttons –

LG K51 Home & Back Button/How to Close Apps

17. Lacks NFC / Android Pay

lg k51 nfc

One very prominent & significant feature removed from the LG K51 is NFC / Android Pay. The omission of NFC makes me wonder, whether the K51 is an upgrade or downgrade from K40.



does lg k51 have nfc support

I couldn’t find NFC anywhere on LG K51.


Going through the Pros & Cons of LG K51, let’s see where does it fall as compared to K40 –

These are areas where K51 beats K40 

  • Android 10
  • Bigger display with more screen estate
  • USB Type-C Port
  • Rear Triple Cameras

In these fields, K40 excels K51 – 

  • NFC Support
  • Front Camera Flash
  • Face Recognition for screen unlocking


Keeping the above features in mind, you can decide whether K51 is the right upgrade to LG K40.


For any queries or feedback, please leave a comment below.

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